* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;

}

body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(#2b1055,#7597de);
}

section{
    position: relative;
    width: 100%;
    height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;  /* 溢出隐藏 */
}
section img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    pointer-events: none;
}

section img#moon {
    top: -100%;
    mix-blend-mode: screen; /*描述了元素的内容应该与元素的直系父元素的内容和元素的背景如何混合。 */
}

section img#stars {
    top: -100%;
    height: 100%;
    object-fit: cover; /* 图片在div中的展示方式 */
   
}

section img#mountains_behind {
    bottom: -100%;
    top: inherit;

}

section img#mountains_front {
    bottom: -100%;
    top: inherit;
    z-index: 100;
}

#text { 
    position: absolute;
    color: #fff;
    font-size: 8vw;
    font-weight: 200;
    z-index: 200;
    margin-right: -3000px;
}

#text span{ 
    font-weight: 700;
}
#btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%,-50%);
    margin-top: 100px;
    text-decoration: none; /*下划线 无 */
    display: inline-block;
    padding: 8px 50px;
    background: #fff;
    border-radius: 40px;
    font-size: 1.4em;
    color: #2b1055;
    z-index: 200;
}